Protective head wear has been used for thousands of years with such use being based on the idea of protecting a user's head from injury. The earliest forms of protective head wear were worn by military soldiers, who used such equipment to protect their heads against blows from various weapons, such as swords and arrows.
Although protective head wear is still used in modern military applications, other uses of protective head wear have evolved over the past several hundred years to include equipment for various recreational and civilian purposes, such as construction, mining, transportation, medical purposes, and sports. The use of protective head wear in sports has grown to be perhaps the most widespread, and includes sports such as American football, baseball, hockey, auto and motorcycle racing, rock climbing, lacrosse, skiing, equestrian sports, cricket, cycling, and other various types of sports.
The shape and size of protective head wear often times varies, and depends on the particular needs and circumstances of the purpose for which it will be applied. For example, a bicycle helmet may be designed to be well ventilated and aerodynamic, while a rock climbing helmet may be designed to be lightweight and less-bulky.
In some applications, an article of protective head wear, such as a helmet, includes a portion that covers and, in some cases, extends below the user's ear. Examples of this design include American football helmets, baseball helmets, and auto racing helmets.
Traditionally, the portion that covers the user's ear may include an aperture so that the user is still able to hear outside sound while wearing the helmet. In some cases, however, the portion that covers the user's ear is solid, and does not include an aperture near the ear; in this case the user may have trouble hearing outside sounds, if he or she is able to hear them at all.
Where the protective head wear includes an aperture near the user's ear, noise is able to enter into the user's ear, and in some cases may cause discomfort and hamper the user's ability to perform various functions. A sport in which this problem often arises is American football. American football helmets are traditionally designed with a portion of the helmet extending over and below the user's ear, and include an aperture near the user's ear. American football players often times experience confusion on the field due to crowd noise, which is able to enter through the above mentioned aperture.
In instances where a user may want to hear an outside sound, but where the protective head wear does not include an aperture near the user's ear, the user may have trouble hearing the sound.